Conventional methods for preparing pure nanodrugs (PNDs) include re-precipitation which is also called solvent-exchange process. The solvent-exchange process is generally based on the relative solubility of the drug compound in two immiscible liquids such as water and an organic solvent. When the organic solvent containing the drug compounds comes into the contact with the non-solvent such as water, the drug compound will be precipitated to form particles. However, there are several drawbacks associated with such processes, for example, large batch-to-batch variations, low production rates and relatively large particle sizes.
Recently, a method for preparing size controllable nanodrugs (NDs) has been described representing an anodized aluminum oxide (AAO) template-assisted method. Although this AAO template-assisted approach allows the production of nanoparticles with improved reproducibility and allows for a higher production rate, the use of the organic template is associated with several problems such as contamination and biodegradation of the possible trace amount of aluminum residues.
Accordingly, there remains a strong need for developing an environmentally friendly and effective process to prepare nanoparticles of compounds, especially drug compounds, with small particle size, high production rate and high reproducibility. Especially when preparing nanoparticles of drug compounds, it is very important to ensure a sufficient purity while avoiding traces of compounds which could negatively impact health.